Behavioral Modeling of a Radio Frequency Wireless Power Transfer System for Batteryless Internet of Things Applications

The evolution of wireless communications technologies is fostering new Internet of Things (IoT) applications. However, sustainable IoT development requires new batteryless and eco-friendly device designs, contributing to cost reduction, lower maintenance, and less environmental damage compared to typical battery-powered IoT. Inspired by such goals, this paper presents a behavioral modeling of a radio frequency wireless power transfer (WPT) system for batteryless IoT applications. We consider a supercapacitor as the energy storage element and analytically describe its behavior during energy harvesting as well as during information transmission. To validate our proposed model, we compare it with measurement results from the literature, showing perfect agreement. Furthermore, we also compare the proposed model with the state-of-the-art, highlighting important differences when considering the effect of the elements preceding and succeeding the supercapacitor into the recharging time, which have critical implications in the design of charging and transmission cycles.